/**
  ******************************************************************************
  * @file    TIM/TIM_PrescalerSelection/Src/main.c
  * @author  MCD Application Team
  * @brief   This sample code shows how to use STM32F7xx TIM HAL API to generate
  *          1 signal in PWM.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2016 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/** @addtogroup STM32F7xx_HAL_Examples
  * @{
  */

/** @addtogroup TIM_PrescalerSelection
  * @{
  */

/* Private typedef -----------------------------------------------------------*/
#define  PERIOD_VALUE       (uint32_t)(2000 - 1)  /* Period Value  */
#define  PULSE1_VALUE       (uint32_t)(1000 - 1)  /* Capture Compare 1 Value  */

/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Timer handler declaration */
TIM_HandleTypeDef    TimHandle;

/* Timer Output Compare Configuration Structure declaration */
TIM_OC_InitTypeDef sConfig;

/* Counter Prescaler value */
uint32_t uhPrescalerValue = 0;

/* Private function prototypes -----------------------------------------------*/
static void MPU_Config(void);
static void SystemClock_Config(void);
static void Error_Handler(void);
static void CPU_CACHE_Enable(void);

/* Private functions ---------------------------------------------------------*/

/**
  * @brief  Main program.
  * @param  None
  * @retval None
  */
int main(void)
{
  /* Configure the MPU attributes */
  MPU_Config();

  /* Enable the CPU Cache */
  CPU_CACHE_Enable();

  /* STM32F7xx HAL library initialization:
       - Configure the Flash prefetch
       - Systick timer is configured by default as source of time base, but user 
         can eventually implement his proper time base source (a general purpose 
         timer for example or other time source), keeping in mind that Time base 
         duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and 
         handled in milliseconds basis.
       - Set NVIC Group Priority to 4
       - Low Level Initialization
     */
  HAL_Init();

  /* Configure LED3 */
  BSP_LED_Init(LED3);

  /* Configure the system clock to 216 MHz */
  SystemClock_Config();

  /* Compute the prescaler value to have TIM3 counter clock equal to 43200000 Hz */
  uhPrescalerValue = (uint32_t)(SystemCoreClock / 43200000) - 1;


  /*##-1- Configure the TIM peripheral #######################################*/
  /* -----------------------------------------------------------------------
  TIM3 Configuration: generate 1 PWM signal with clock prescaler selection feature activated using __HAL_RCC_TIMCLKPRESCALER()
  which allow to double the output frequency.

  In this example TIM3 input clock (TIM3CLK) is set to 4 * APB1 clock (PCLK1), since 
  Timer clock prescalers selection activated (TIMPRE bit from RCC_DCKCFGR register is set).   
  TIM3CLK = 4 * PCLK1  
  PCLK1 = HCLK / 4 
  => TIM3CLK = HCLK = SystemCoreClock

  For TIM3CLK equal to SystemCoreClock and prescaler equal to (5 - 1), TIM3 counter clock 
  is computed as follows:
  TIM3 counter clock = TIM3CLK / (Prescaler + 1)
                     = SystemCoreClock / (Prescaler + 1)
                     = 43.2MHz

  For ARR equal to (2000 - 1), the TIM3 output clock is computed as follows:
  TIM3 output clock = TIM3 counter clock / (ARR + 1)
                    = 21.6KHZ
                     
  The TIM3 CCR1 register value is equal to 1000, so the TIM3 Channel 1 generates a 
  PWM signal with a frequency equal to 21.6 KHz and a duty cycle equal to 50%:

  TIM3 Channel1 duty cycle = (TIM3_CCR1/ TIM3_ARR + 1)* 100 = 50%

    Note:
     SystemCoreClock variable holds HCLK frequency and is defined in system_stm32f7xx.c file.
     Each time the core clock (HCLK) changes, user had to update SystemCoreClock
     variable value. Otherwise, any configuration based on this variable will be incorrect.
     This variable is updated in three ways:
      1) by calling CMSIS function SystemCoreClockUpdate()
      2) by calling HAL API function HAL_RCC_GetSysClockFreq()
      3) each time HAL_RCC_ClockConfig() is called to configure the system clock frequency
  ----------------------------------------------------------------------- */

  /* Timer clock prescalers selection activation */ 
  __HAL_RCC_TIMCLKPRESCALER(RCC_TIMPRES_ACTIVATED);

  /* Initialize TIMx peripheral as follows:
       + Prescaler = (SystemCoreClock / 43200000) - 1
       + Period = (2000 - 1)
       + ClockDivision = 0
       + Counter direction = Up
  */
  TimHandle.Instance = TIMx;

  TimHandle.Init.Prescaler         = uhPrescalerValue;
  TimHandle.Init.Period            = PERIOD_VALUE;
  TimHandle.Init.ClockDivision     = 0;
  TimHandle.Init.CounterMode       = TIM_COUNTERMODE_UP;
  TimHandle.Init.RepetitionCounter = 0;
  TimHandle.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_PWM_Init(&TimHandle) != HAL_OK)
  {
    /* Initialization Error */
    Error_Handler();
  }

  /*##-2- Configure the PWM channels #########################################*/
  /* Common configuration for all channels */
  sConfig.OCMode       = TIM_OCMODE_PWM1;
  sConfig.OCPolarity   = TIM_OCPOLARITY_HIGH;
  sConfig.OCFastMode   = TIM_OCFAST_DISABLE;
  sConfig.OCNPolarity  = TIM_OCNPOLARITY_HIGH;
  sConfig.OCNIdleState = TIM_OCNIDLESTATE_RESET;
  sConfig.OCIdleState  = TIM_OCIDLESTATE_RESET;

  /* Set the pulse value for channel 1 */
  sConfig.Pulse = PULSE1_VALUE;
  if (HAL_TIM_PWM_ConfigChannel(&TimHandle, &sConfig, TIM_CHANNEL_1) != HAL_OK)
  {
    /* Configuration Error */
    Error_Handler();
  }
  
  /*##-3- Start PWM signals generation #######################################*/ 
  /* Start channel 1 */
  if (HAL_TIM_PWM_Start(&TimHandle, TIM_CHANNEL_1) != HAL_OK)
  {
    /* PWM Generation Error */
    Error_Handler();
  }
  /* Start channel 2 */
  if (HAL_TIM_PWM_Start(&TimHandle, TIM_CHANNEL_2) != HAL_OK)
  {
    /* PWM Generation Error */
    Error_Handler();
  }
  /* Start channel 3 */
  if (HAL_TIM_PWM_Start(&TimHandle, TIM_CHANNEL_3) != HAL_OK)
  {
    /* PWM generation Error */
    Error_Handler();
  }
  /* Start channel 4 */
  if (HAL_TIM_PWM_Start(&TimHandle, TIM_CHANNEL_4) != HAL_OK)
  {
    /* PWM generation Error */
    Error_Handler();
  }

  while (1)
  {
  }

}


/**
* @brief  CPU L1-Cache enable.
* @param  None
* @retval None
*/
static void CPU_CACHE_Enable(void)
{
  /* Enable I-Cache */
  SCB_EnableICache();

  /* Enable D-Cache */
  SCB_EnableDCache();
}

/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
static void Error_Handler(void)
{
  /* Turn LED3 on */
  BSP_LED_On(LED3);
  while (1)
  {
  }
}

/**
  * @brief  System Clock Configuration
  *         The system Clock is configured as follow : 
  *            System Clock source            = PLL (HSE)
  *            SYSCLK(Hz)                     = 216000000
  *            HCLK(Hz)                       = 216000000
  *            AHB Prescaler                  = 1
  *            APB1 Prescaler                 = 4
  *            APB2 Prescaler                 = 2
  *            HSE Frequency(Hz)              = 25000000
  *            PLL_M                          = 25
  *            PLL_N                          = 432
  *            PLL_P                          = 2
  *            PLL_Q                          = 9
  *            PLL_R                          = 7
  *            VDD(V)                         = 3.3
  *            Main regulator output voltage  = Scale1 mode
  *            Flash Latency(WS)              = 7
  * @param  None
  * @retval None
  */
static void SystemClock_Config(void)
{
  RCC_ClkInitTypeDef RCC_ClkInitStruct;
  RCC_OscInitTypeDef RCC_OscInitStruct;
  HAL_StatusTypeDef  ret = HAL_OK;
  
  /* Enable Power Control clock */
  __HAL_RCC_PWR_CLK_ENABLE();
  
  /* The voltage scaling allows optimizing the power consumption when the device is 
     clocked below the maximum system frequency, to update the voltage scaling value 
     regarding system frequency refer to product datasheet.  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  /* Enable HSE Oscillator and activate PLL with HSE as source */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLM = 25;
  RCC_OscInitStruct.PLL.PLLN = 432;  
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 9;
  RCC_OscInitStruct.PLL.PLLR = 7;
  
  ret = HAL_RCC_OscConfig(&RCC_OscInitStruct);
  if(ret != HAL_OK)
  {
    while(1) { ; }
  }
  
  /* Activate the OverDrive to reach the 216 MHz Frequency */  
  ret = HAL_PWREx_EnableOverDrive();
  if(ret != HAL_OK)
  {
    while(1) { ; }
  }
  
  /* Select PLL as system clock source and configure the HCLK, PCLK1 and PCLK2 clocks dividers */
  RCC_ClkInitStruct.ClockType = (RCC_CLOCKTYPE_SYSCLK | RCC_CLOCKTYPE_HCLK | RCC_CLOCKTYPE_PCLK1 | RCC_CLOCKTYPE_PCLK2);
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;  
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2; 
  
  ret = HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_7);
  if(ret != HAL_OK)
  {
    while(1) { ; }
  }  
}


/**
  * @brief  Configure the MPU attributes
  * @param  None
  * @retval None
  */
static void MPU_Config(void)
{
  MPU_Region_InitTypeDef MPU_InitStruct;

  /* Disable the MPU */
  HAL_MPU_Disable();

  /* Configure the MPU as Strongly ordered for not defined regions */
  MPU_InitStruct.Enable = MPU_REGION_ENABLE;
  MPU_InitStruct.BaseAddress = 0x00;
  MPU_InitStruct.Size = MPU_REGION_SIZE_4GB;
  MPU_InitStruct.AccessPermission = MPU_REGION_NO_ACCESS;
  MPU_InitStruct.IsBufferable = MPU_ACCESS_NOT_BUFFERABLE;
  MPU_InitStruct.IsCacheable = MPU_ACCESS_NOT_CACHEABLE;
  MPU_InitStruct.IsShareable = MPU_ACCESS_SHAREABLE;
  MPU_InitStruct.Number = MPU_REGION_NUMBER0;
  MPU_InitStruct.TypeExtField = MPU_TEX_LEVEL0;
  MPU_InitStruct.SubRegionDisable = 0x87;
  MPU_InitStruct.DisableExec = MPU_INSTRUCTION_ACCESS_DISABLE;

  HAL_MPU_ConfigRegion(&MPU_InitStruct);

  /* Enable the MPU */
  HAL_MPU_Enable(MPU_PRIVILEGED_DEFAULT);
}

#ifdef  USE_FULL_ASSERT

/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* User can add his own implementation to report the file name and line number,
     ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */

  /* Infinite loop */
  while (1)
  {
  }
}

#endif

/**
  * @}
  */

/**
  * @}
  */

